The subject matter disclosed herein relates to detection of inter-area low frequency oscillations in power lines.
Modern power systems are becoming increasingly interconnected to each other for the benefits of increased reliability, reduced operation cost, improved power quality, and reduced necessary spinning reserve. However, the interconnected power systems may also bring some technical challenges. Of them, inter-area low frequency oscillations have become one of the major threats to reliable operations of large-scale power systems. Inter-area oscillations may occur when large synchronously interconnected power systems have rotor angle/frequency/power/voltage/current swings between the synchronous generators of a first subsystem (or of large power plant) and another subsystem (or other subsystems).
Inter-area oscillations not only limit the amount of power transfer, but also threaten the system security, because they may lead to system instability, which may result in cascading outages in the system. Therefore, it is desirable to identify the characteristics of the inter-area oscillations, including oscillation frequency and damping ratio, so that proper actions can be taken based on the identification results to improve system damping and maintain system stability.